Late reply but what're you doing for vestibular therapy? BTW right there with you and your doctor and inconclusive test circles/ dizzy symptoms/ chronic forward neck posture/ straight neck x-ray. Can't buy a denneroll outright as only Chiropractors are able to, but my Blair Chiro recommended this item which is comparable, just not as aggressive. I just started using it 3 times a day and do get relief while I'm on it. So think it's just one of those things that will take a while to fix.
No problem! This is the exact one I use.
https://www.amazon.com/Neck-Relief®-Neck-Support-Chiropractic-Cervipedic®/dp/B00FSOUNSW